664240356 has 36 divisors (see below), whose sum is σ = 1808211132. Its totient is φ = 204381504.

The previous prime is 664240351. The next prime is 664240373. The reversal of 664240356 is 653042466.

664240356 is a `hidden beast` number, since 6 + 64 + 240 + 356 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 105390756 + 558849600 = 10266^2 + 23640^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 664240356.

It is not an unprimeable number, because it can be changed into a prime (664240351) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 709191 + ... + 710126.

It is an arithmetic number, because the mean of its divisors is an integer number (50228087).

Almost surely, 2^664240356 is an apocalyptic number.

It is an amenable number.

664240356 is an abundant number, since it is smaller than the sum of its proper divisors (1143970776).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664240356 is a wasteful number, since it uses less digits than its factorization.

664240356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1419340 (or 1419335 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The square root of 664240356 is about 25772.8608423667. The cubic root of 664240356 is about 872.5193876421.

The spelling of 664240356 in words is "six hundred sixty-four million, two hundred forty thousand, three hundred fifty-six".